Investors wiped nearly 20 per cent off Inmarsat’s market value yesterday after the satellite telecoms company admitted that sales in its core shipping business would fall flat as the pull-back of troops in Afghanistan hit revenue.

The London-based communications provider had expected sales in its maritime division, where it provides voice and data services to military and commercial ships, to grow by 2 to 4 per cent but now expects no growth.

Inmarsat previously warned that a large number of its maritime customers had started to upgrade to satellite terminals on ships that are cheaper to use than older models